Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to an apparatus and method for improving amplitude estimation of a received signal based on dedicated pilots and transmit power control commands (TPC) commands, thereby providing consistent service in a wireless communication system.
Wireless communication networks are widely deployed to provide various communication services such as telephony, video, data, messaging, broadcasts, and so on. Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources. One example of such a network is the UMTS Terrestrial Radio Access Network (UTRAN). The UTRAN is the radio access network (RAN) defined as a part of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile phone technology supported by the 3rd Generation Partnership Project (3GPP). The UMTS, which is the successor to Global System for Mobile Communications (GSM) technologies, currently supports various air interface standards, such as Wideband-Code Division Multiple Access (W-CDMA), Time Division-Code Division Multiple Access (TD-CDMA), and Time Division-Synchronous Code Division Multiple Access (TD-SCDMA). The UMTS also supports enhanced 3G data communications protocols, such as High Speed Packet Access (HSDPA), which provides higher data transfer speeds and capacity to associated UMTS networks.
As the demand for mobile broadband access continues to increase, research and development continue to advance the UMTS technologies not only to meet the growing demand for mobile broadband access, but to advance and enhance the user experience with mobile communications.
Generally, in Code-Division-Multiple-Access (CDMA) systems, forward and reverse links periodically transmit dedicated pilot symbols every slot to estimate the channel. Signal-to-Noise Ratio (SNR) estimation based on those dedicated pilots is used for power control to maintain the required link quality while using the minimum transmitted power. The performance of the power control algorithm depends significantly on a good SNR estimate for proper operation. While noise power estimation can be taken from different sources (e.g., common pilot channel), the power of the relevant codeword can be estimated only from the codeword itself. However, since only a few dedicated pilots are received, power estimation based on the few dedicated pilots may be noisy and unreliable.
Thus, aspects of this apparatus and method for improving amplitude estimation of a received signal to provide consistent service in a wireless communication system.